As per systems theory, the parts of the tree will include the following.
- Root: This part of the tree is buried in the soil and is directly connected to the stem. It performs two main functions. It sucks nutrients from the soil and supplies to the while tree. The roots also helps the stem to remain upright.
- Stem: This part of the tree helps the tree to rise high above the ground level. This enables the tree to t more sunshine. It also restricts access to the tree's leaves and fruits by animals. The stem also provides anchoring to the trees branches.
- Branches: The branches are anchored to the stem and serve the purpose of supporting leaves, flowers and fruits of tree. The branches are like a constructed in a way that enables the tree to form a large canopy that enables it to have a large number of leaves that collect sunshine from a wider area.
- Leaves: These are attached to branches. Leaves perform the function of receiving sunshine, absorbing carbon dioxide from the atmosphere, and preparing food for the tree, by the process of photo-synthesis, using nutrients received from soil, carbon dioxide, and sunlight. In this process the leaves release oxygen in the atmosphere.
- The internal conveying systems: This system conveys nutrients in the soil to the leaves, and the food prepared by the leaves to all the parts of the tree.
I have not included flowers and fruits as part of the tree as a system. Instead I would like to qualify them as the output of the tree. Further it is worthwhile noting that flowers ant fruits are not two separate parts but different stages of development of the same part. Fruit it self may be considered as a subsystem with multiple parts. Also the seed in the part becomes the means of growth of new trees.
The tree as a system uses the following inputs.
- Water and nutrients from the soil.
- carbon dioxide
- External agents like bees and wind to aid in pollination.
Output from the tree includes the following:
- Flowers including nectar for the bees.
- Fruits including seeds for growth of other trees
- Shade and protection from rain
- Oxygen to maintain balance of oxygen in the atmosphere. It is worthwhile noting that animals use oxygen and release carbon dioxide. Without plants to convert carbon dioxide back in to oxygen, the level of carbon dioxide in the atmosphere will rise to a level where life will soon become impossible. Also without plants to absorb the energy of sun, the temperature on earth will rise to unbearable levels.
- Prevention of erosion of soil with flow or rain and flood water.
The tree is an open system, interacting with many other systems. These include:
- All animals, including humans that eat its fruits.
- All the birds that perch on its branches and also make their nest in trees. Some animals also use tree as their dwelling place.
- Bees that such nectar from flowers and help in fertilization.
- All animals that use tree as shelter.
- The soil system.
- The atmospheric system.
- The sun that provides sunlight